JP2009149891A - Lubricating oil composition for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricating oil composition capable of affording protection against wear and a reduction of friction to internal combustion engines. <P>SOLUTION: The lubricating oil composition for high-performance engines comprises a Group III base oil, and a combination of ester base stocks comprising following components: (i) an ester base stock having a kinematic viscosity at 100°C of about 2-10 cSt, (ii) an ester base stock having a kinematic viscosity at 100°C of about 10-50 cSt, and (iii) an ester base stock having a kinematic viscosity at 100°C of higher than about 100 cSt. Furthermore, the lubricating oil composition may comprise at least one additive. Methods for producing and using the lubricating oil composition are described. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides a lubricating oil composition for an internal combustion engine. The composition provided in the present invention comprises a combination of a Group III base stock and an ester base stock. Also described are methods for making and using the lubricating oil composition.

  High power engines require higher wear protection and less energy loss even under extremely severe operating conditions. Such engine lubricating oil compositions are required to provide extreme pressure performance without being corroded by another extreme pressure agent. Modern racing oils have been formulated by improving conventional oils or lubricating oils used in passenger cars. Oils formulated in this way do not optimally and efficiently meet the performance requirements imposed on racing oils. Accordingly, there remains a need for new lubricating oil formulations suitable for use in high power engines.

  The present invention provides a lubricating oil composition that provides wear protection and reduced friction for an internal combustion engine.

  The present invention provides a lubricating oil composition that provides wear protection and reduced friction for an internal combustion engine. In one embodiment, the lubricating oil composition comprises a combination of a Group III base oil and an ester base stock.

  In some embodiments, the Group III base oil is present in an amount greater than about 50%, 60%, or about 70% by weight of the lubricating oil composition.

  In some embodiments, the ester base stock combination comprises three or more ester base stocks. In some embodiments, the ester base stock combination comprises three ester base stocks. In some embodiments, the ester base stock combination includes the following components: (i) an ester base stock having a kinematic viscosity of about 2-10 cSt at 100 ° C., and (ii) about 10-50 cSt at 100 ° C. or Ester base stocks greater than 10 and up to 50 cSt, and (iii) ester base stocks having a kinematic viscosity of greater than about 100 cSt at 100 ° C. In some embodiments, the amount of ester base stock combination in the lubricating oil composition is less than about 50% by weight of the lubricating oil composition. In certain embodiments, the amount of ester base stock combination in the lubricating oil composition is less than about 45%, about 40% or about 35% by weight of the lubricating oil composition.

  The present invention also provides a method for producing a lubricating oil composition. In one embodiment, the method includes mixing a combination of (a) a III base oil and (b) an ester base stock comprising the following components: (i) a kinematic viscosity at 100 ° C. An ester base oil of 10 cSt, (ii) an ester base oil having a kinematic viscosity higher than 10 at 100 ° C. and up to 50 cSt, and (iii) an ester base oil having a kinematic viscosity higher than 100 cSt at 100 ° C. (See D Lubricant, column 84)

  The present invention also provides a method of lubricating an internal combustion engine using the lubricating oil composition provided by the present invention. In one embodiment, the method includes applying a lubricating oil composition to the engine. In one aspect, the lubricating oil composition provided by the present invention is useful for high power engines such as racing car engines, sports car engines, and the like. In one embodiment, the lubricating oil composition provides higher wear protection for high power engines. In another aspect, the lubricating oil composition results in less energy loss even under the severe operating conditions of high power engines.

  In certain embodiments, the lubricating oil compositions disclosed herein are substantially free of viscosity index improvers. In another aspect, the lubricating oil compositions disclosed herein do not include a viscosity index improver.

  In some embodiments, the lubricating oil compositions disclosed herein can further include antioxidants, antiwear additives, detergents, rust inhibitors, demulsifiers, friction modifiers, multifunctional additives, pour point depressants. And at least one lubricating oil additive selected from the group consisting of agents, antifoaming agents, metal deactivators, dispersants, corrosion inhibitors, thermal stability improvers, dyes, markers and combinations thereof.

  Other aspects will become apparent from the following description and some of them will be described.

  In one aspect, the lubricating oil composition provided by the present invention is suitable for high power engines such as those found in racing cars and sports cars. In one aspect, the lubricating oil composition of the present invention provides higher wear protection and less energy loss, even under extremely severe operating conditions due to high power engines. In one aspect, the extreme pressure performance of such engines has been proven by improvements in the Falex test (ASTM D3233 method B). In one aspect, the lubricating oil composition of the present invention minimizes or avoids the corrosive effects of such extreme pressure agents with the lubricating oil composition by minimizing or not using other extreme pressure agents. it can. In some embodiments, the lubricating oil formulation provided by the present invention improves the shear stability of the oil. In one aspect, the lubricating oil composition of the present invention improves hydraulic stability.

FIG. 1 is a chart showing the results of an MTM traction test at a SRR (slip ratio between a sphere and a disk) of 25% for a comparative lubricating oil composition and a lubricating oil composition provided by the present invention. FIG. 2 is a chart showing the results of an MTM traction test at a SRR (slip ratio between a sphere and a disk) of 50% for a comparative lubricating oil composition and the lubricating oil composition provided by the present invention. FIG. 3 is a chart showing the results of an MTM traction test at a SRR (slip ratio between a sphere and a disk) of 75% for a comparative lubricating oil composition and a lubricating oil composition provided by the present invention. FIG. 4 is a chart showing the results of an MTM traction test at a SRR (slip ratio between a sphere and a disk) of 100% for a comparative lubricating oil composition and the lubricating oil composition provided by the present invention.

[Definition]
In order to facilitate understanding of the content of the invention disclosed herein, a number of terms, abbreviations or other abbreviations used herein are defined below. Any terms, abbreviations or abbreviations that are not defined should be construed to have their ordinary meaning as used by those skilled in the art simultaneously with the disclosure of this application.

  A “major amount” of base oil means that the amount of base oil is at least 40% by weight of the lubricating oil composition. In some embodiments, the “major amount” of base oil is greater than 50%, greater than 60%, greater than 70%, greater than 80%, or greater than 90% by weight of the base oil composition. Means oil.

  “Sulfated ash” means the amount of a metal-containing additive (eg, calcium, magnesium, molybdenum, zinc, etc.) in a lubricating oil, and can generally be measured by ASTM D874, which is also incorporated herein by reference. To do.

  “Substantially free” of a compound having a composition means that the composition is less than 20% by weight, less than 10% by weight, less than 5% by weight, less than 4% by weight, less than 3% by weight based on the total weight of the composition. Less than 2%, less than 2%, less than 1%, less than 0.5%, less than 0.1%, or less than 0.01% by weight.

  “Free” of a compound with a composition means that the composition contains only 0.001% to 0% by weight of the compound, based on the total weight of the composition.

All numerical values disclosed in the following description are approximate values, whether or not the vocabulary “about” or “approximately” is used in connection therewith. The numbers can vary by 1 percent, 2 percent, 5 percent, or sometimes 10-20 percent. Whenever a numerical range is disclosed with a lower limit R ^L and an upper limit R ^U , any numerical value within that range is explicitly disclosed. Specifically, the following numerical values in the range are explicitly disclosed: R = R ^L + k ^* (R ^U −R ^L ), where k is a variable that increases by 1 percent in the range of 1 percent to 100 percent. I.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, ... 50 percent, 51 percent, 52 percent, ... 95 percent, 96 percent, 97 percent, 98 percent, 99 Percent or 100 percent. Furthermore, any numerical range defined by two numerical values R as defined above is clearly disclosed.

The present invention provides a lubricating oil for an internal combustion engine comprising a) a Group III base oil, and b) a combination of an ester base oil containing the following components, and optionally c) one or more lubricating oil additives. The composition is:
(I) an ester base oil having a kinematic viscosity at 100 ° C. of 2-10 cSt,
(Ii) an ester base oil having a 100 ° C. kinematic viscosity of 10 to 50 cSt or higher than 10 and up to 50 cSt, and (iii) an ester base oil having a 100 ° C. kinematic viscosity higher than 100 cSt.

A) Base oil
Group III base oils are described in American Petroleum Institute (API) Publication 1509, 16th edition, Appendix E. Type III base oil is defined to have the following minimum characteristics: E.I. Sulfur ≧ 0.03%, saturation ≧ 90%, and viscosity index ≧ 120 as measured by the ASTM method described in Table 1. In one aspect, the saturation amount of the Group III base oil is at least about 95% by weight and in one aspect at least about 98% by weight. In one aspect, the sulfur content is at most about 0.02% by weight, and in another aspect, at most about 0.01% by weight. In one aspect, the Group III base oil has a viscosity index of about 125, and in another aspect, greater than 130.

  The type III base oil used in the present invention can be obtained from a number of different raw materials. For example, base oils can be produced using a variety of different methods including, but not limited to, distillation, solvent refining, hydrotreating, oligomerization and rerefining. Rerefined feedstock is generally substantially free of materials introduced by manufacturing, contamination, or previous use.

  In one aspect, the Group III base oil is derived from natural lubricating oils, synthetic lubricating oils or mixtures thereof. Examples of the lubricating base oil include base oil obtained by isomerization of synthetic wax and crude wax, and hydrocracked base oil produced by hydrocracking aromatic and polar components of crude oil. . Examples of the hydrocarbon synthetic oil include an oil produced by a hydrocarbon synthesis method using carbon monoxide gas and hydrogen gas, for example, a Fischer-Tropsch method.

  In one aspect, the Group III base oil used in the present invention is derived from a natural feedstock (rather than derived from a synthetic feedstock) and refined to show the performance and viscosity parameters of the synthetic base oil.

  In some embodiments, natural lubricating oils can include animal oils, vegetable oils (eg, rapeseed oil, castor oil and lard oil), petroleum oils, mineral oils, and oils derived from coal or shale.

  Base oils may be derived from unrefined, refined, rerefined oils or mixtures thereof. In one aspect, the unrefined oil is obtained directly from natural or synthetic raw materials (eg, coal, shale or tar sand bitumen) without further purification or processing. Examples of unrefined oils include shale oil obtained directly by retorting, petroleum oil obtained directly by distillation, or ester oil obtained directly by an esterification method, each without further treatment. Can be used. Refined oils are the same as unrefined oils except that they have been treated in one or more refining steps to improve one or more properties. Suitable purification techniques include distillation, hydrocracking, hydrotreating, dewaxing, solvent extraction, acid or base extraction, filtration, and percolate, all known to those skilled in the art. The rerefined oil is obtained by treating the used oil in the same manner as used to obtain the refined oil. These rerefined oils are also known as reclaimed or reprocessed oils and are often further processed by techniques aimed at removing used additives and oil breakdown products.

  Base oils derived from wax hydroisomerization can also be used alone or in combination with the natural and / or synthetic base oils. Such wax isomerate oils are produced by hydroisomerizing natural or synthetic waxes or mixtures thereof using a hydroisomerization catalyst.

  Examples of Group III base oils are disclosed in US Pat. Nos. 6,503,872, 6,664,576, and 6,713,438. Typical Group III base oils include UCBO4R, UCBO7R, TEXHVI feedstocks such as TEXHVI-100N (saturation 95%, viscosity index 125 and sulfur 0.02%), TEXHVI-70N (saturation 97.8%, Viscosity index 123 and sulfur 0.02%), "MOTIVA" TEXHVI90N-100N (saturation 100%, viscosity index 125 and sulfur 0.01%), and "MOTIVA" TEXHVI75N (saturation 100%, viscosity index 125 and sulfur) 0.0%). In one aspect, the Group III base oil used in the lubricating oil composition provided by the present invention is UCBO4R or UCBO7R.

  In certain embodiments, the amount of Group III base oil in the lubricating oil composition of the present invention is greater than about 40% by total weight of the composition. In some embodiments, the amount of Group III base oil in the lubricating oil composition of the present invention is greater than about 50% by total weight of the composition. In certain embodiments, the amount of Group III base oil in the lubricating oil composition of the present invention is about 50% to about 90% by total weight of the composition. In some embodiments, the amount of Group III base oil in the lubricating oil composition of the present invention is from about 50% to about 70% by total weight of the composition. In some embodiments, the amount of Group III base oil in the lubricating oil composition of the present invention is from about 50% to about 60% by total weight of the composition. In certain embodiments, the amount of Group III base oil in the lubricating oil composition of the present invention is about 45%, 50%, 52%, 54%, 56%, 58%, 60%, 62% by total weight of the composition. 64%, 66%, 68%, 70%, 75%, 80%, 85%, or about 90%. In one aspect, the amount of Group III base oil in the lubricating oil composition of the present invention is about 54% or 58% by total weight of the composition.

B) Combination of ester base stock In one embodiment, the ester base stock combination used in the lubricating oil composition of the present invention comprises at least three ester base stocks. In some embodiments, the ester base stock combination includes three ester base stocks. In some embodiments, the ester base stock combination includes the following components: (i) an ester base stock having a kinematic viscosity of about 2-10 cSt at 100 ° C., and (ii) an ester having a kinematic viscosity of about 10-50 cSt at 100 ° C. A base stock, and (iii) an ester base stock having a kinematic viscosity greater than about 100 cSt at 100 ° C.

  In some embodiments, the ester base stock combination used in the lubricating oil composition of the present invention comprises at least three ester base stocks. In some embodiments, the ester base stock combination includes three ester base stocks. In some embodiments, the ester base stock combination includes the following components: (i) an ester base stock having a kinematic viscosity of 2-10 cSt at 100 ° C, and (ii) an ester having a kinematic viscosity of greater than 10 and up to 50 cSt at 100 ° C. A base stock, and (iii) an ester base stock having a kinematic viscosity greater than about 100 cSt at 100 ° C.

  In some embodiments, the amount of ester base stock combination in the lubricating oil composition is less than about 50% by weight of the lubricating oil composition. In some embodiments, the amount of ester base stock combination in the lubricating oil composition is less than about 50%, about 45%, about 40% or about 35% by weight of the lubricating oil composition. In some embodiments, the amount of the ester base stock combination in the lubricating oil composition is about 49%, about 47%, about 45%, about 43%, about 40% by weight of the lubricating oil composition, About 38%, about 36%, about 34%, about 30%, about 28%, about 25%, about 23%, about 20%, about 15%, or about 10% It is. In one aspect, the amount of ester base stock combination in the lubricating oil composition is about 38% or about 34% by weight of the lubricating oil composition.

(Ester base oil having a kinematic viscosity at 100 ° C. of 2-10 cSt)
In one embodiment, the ester base stock oil having a kinematic viscosity at 100 ° C. of 2-10 cSt comprises an ester of an aliphatic dibasic acid having 4-14 carbon atoms and an alcohol having 4-14 carbon atoms. In one embodiment, the aliphatic dibasic acids having 4 to 14 carbon atoms include succinic acid, glutaric acid, adipic acid, piperic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassic acid, and Mention may be made of tetradecanedioic acid. Examples of alcohols having 4 to 14 carbon atoms include n-butanol, isobutanol, n-amyl alcohol, isoamyl alcohol, n-hexanol, 2-ethylbutanol, cyclohexanol, n-heptanol, isoheptanol, methyl Cyclohexanol, n-octanol, dimaytyl hexanol, 2-ethylhexanol, 2,4,4-trimethylpentanol, isooctanol, 3,5,5-trimethylhexanol, isononanol, isodecanol, isoundecanol, 2-butyl Mention may be made of octanol, tridecanol, and isotetradecanol.

  In one aspect, diesters obtainable from these aliphatic dibasic acids and alcohols include, for example, di (1-ethylpropyl) adipate, di (3-methylbutyl) adipate, di (1,3-methylbutyl) adipate, diester (2-ethylhexyl) adipate, di (isononyl) adipate, di (isodecyl) adipate, di (undecyl) adipate, di (tridecyl) adipate, di (isotetradecyl) adipate, di (2,2,4-trimethylpentyl) Adipate, di [mixed (2-ethylhexyl, isononyl)] adipate, di (1-ethylpropyl) azelate, di (3-methylbutyl) azelate, di (2-ethylbutyl) azelate, di (2-ethylhexyl) azelate, di ( Isooctyl) azelate, di (isonononi) ) Azelate, di (isodecyl) azelate, di (tridecyl) azelate, di [mixed (2-ethylhexyl, isononyl)] azelate, di [mixed (2-ethylhexyl, decyl)] azelate, di [mixed (2-ethylhexyl, isodecyl) )] Azelate, di [mixed (2-ethylhexyl, 2-propylheptyl)] azelate, di (n-butyl) sebacate, di (isobutyl) sebacate, di (1-ethylpropyl) sebacate, di (1,3-methylbutyl) ) Sebacate, di (2-methylbutyl) sebacate, di (2-ethylhexyl) sebacate, di [2- (2-ethylbutoxy) ethyl] sebacate, di (2,2,4-trimethylbenzyl) sebacate, di (isononyl) Sebacate, di (isodecyl) sebacate, di (iso) Decyl) sebacate, di (tridecyl) sebacate, di (isotetradecyl) sebacate, di [mixed (2-ethylhexyl, isononyl)] sebacate, di (2-ethylhexyl) glutarate, di (isoundecyl) glutarate, and di (isotetra) Decyl) glutarate.

  In some embodiments, these diesters have a kinematic viscosity at 100 ° C. of 2-7 cSt, and in another embodiment 2.2-6 cSt. In one embodiment, the low viscosity ester used in the lubricating oil composition of the present invention is Priolube 3960, a diester based on short chain fatty acids with a 100 ° C. kinematic viscosity of 4.5 cSt.

(Ester base oil having a kinematic viscosity at 100 ° C. of about 10 to 50 cSt or higher than about 10 to 50 cSt)
In one embodiment, the ester base stock used in the composition of the present invention has a kinematic viscosity of about 10 to 50 cSt at 100 ° C. In certain embodiments, the kinematic viscosity of the ester base stock used in the composition of the present invention is greater than about 10 and up to 50 cSt at 100 ° C. In some embodiments, the ester base stock having a kinematic viscosity at 100 ° C. higher than 10 and up to 50 cSt comprises polyol esters of C5-C15 monocarboxylic acid. In one aspect, the ester base stock having a kinematic viscosity at 100 ° C. higher than 10 and up to 50 cSt comprises, for example, pentaerythritol trimethylolpropane of C5-C15 monocarboxylic acid and neopentyl glycol soluble esters.

  In one embodiment, the ester is an α-olefin / dicarboxylic acid ester copolymer having a viscosity at 100 ° C. of greater than about 10 and up to 50 cSt or about 20 to 50 cSt, and is represented by Formula I:

In the formula, R ¹ is alkyl, and X ¹ , X ² , X ³ and X ⁴ are each hydrogen, an alkyl group, —R ² —CO ₂ R ³ or —CO ₂ R ⁴ (provided that R 1 ² is alkylene, R ³ and R ⁴ may be the same or different, but each is alkyl, and any two of X ¹ , X ² , X ³ and X ⁴ are CO ₂ R ⁴ ), and x and y may be the same or different, but each is a positive number.

  In some embodiments, the α-olefin / dicarboxylic acid ester copolymer includes an α-olefin having 3 to 20 carbon atoms, and in another embodiment includes an α-olefin having 6 to 18 carbon atoms. Typical α-olefins include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene. , 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, and 1-eicocene.

  In one embodiment, the α-olefin / dicarboxylic acid ester copolymer includes a dicarboxylic acid having an ethylene bond. Examples of dicarboxylic acids include maleic acid, fumaric acid, citraconic acid, mesaconic acid, and itaconic acid. In one aspect, the dicarboxylic acid forms an ester with an alcohol having 1-20 carbon atoms. In another embodiment, the dicarboxylic acid forms an ester with an alcohol having 3-8 carbon atoms. Examples of alcohols include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octane Mention may be made of decanol, nonadecanol, and eicosanol.

  In one embodiment, the α-olefin / dicarboxylic acid ester copolymer is produced by copolymerizing the α-olefin and the dicarboxylic acid ester by methods known to those skilled in the art. A typical method is described in JP-B-58-65246. In one embodiment, the molar ratio of α-olefin (x) to ester (y) of dicarboxylic acid is 1: 9 to 9: 1. In some embodiments, the ester copolymer has a number average molecular weight of 1000 to 3000.

  In one embodiment, the ester base stock used in the present invention is “Ketjenlube 135”, a butanol ester of an α-olefin maleic acid copolymer having an Mn of 1800 and a 100 ° C. viscosity of 35 cSt.

(Ester base oil having a kinematic viscosity at 100 ° C. higher than about 100 cSt)
In some embodiments, the ester base stock having a 100 ° C. kinematic viscosity of greater than about 100 cSt is a complex ester base stock. Such complex ester base stocks are known to those skilled in the art. A typical complex ester base stock is described in US Pat. No. 5,942,475. In one aspect, the complex ester base stock is made from the following materials:
(1) Polyhydroxyl compound represented by the following general formula:
R- (OH) ₂
Wherein R is any aliphatic or alicyclic hydrocarbon group and n is at least 2 provided that the hydrocarbon group contains about 2-20 carbon atoms.
(2) a polybasic acid or polybasic acid anhydride, provided that the ratio of equivalents of polybasic acid to equivalents of alcohol by polyhydroxyl compound is in the range of about 1.6: 1 to 2: 1; and (3) Monohydric alcohols, provided that the ratio of equivalents of monohydric alcohol to polybasic acid is in the range of about 0.84: 1 to 1.2: 1.

  Polyols used in the complex ester base stock include, but are not limited to, neopentyl glycol, trimethylol ethane, trimethylol propane, trimethylol butane, mono-pentaerythritol, pentaerythritol, and di- Mention may be made of pentaerythritol.

Alcohols for use in the complex ester base oil in some embodiments, a branched and / or linear monohydric alcohol C ₅ -C _13. Typical alcohols include, but are not limited to, isopentyl alcohol, isohexyl alcohol, isoheptyl alcohol, n-heptyl alcohol, iso-octyl alcohol (eg 2-ethylhexanol), n- Mention may be made of octyl alcohol, iso-nonyl alcohol (eg 3,5,5-trimethyl-1-hexanol), n-nonyl alcohol, isodecyl alcohol and n-decyl alcohol.

In one embodiment, a polybasic acid or polycarboxylic acids used in the present invention, any C ₂ -C ₁₂ diacids, mention may be made such as adipic acid, azelaic acid, sebacic acid and dodecanedioic acid. In another embodiment, the anhydride used in the complex ester base oil is succinic anhydride, glutaric anhydride, adipic anhydride, maleic anhydride, phthalic anhydride, nadonic anhydride, methyl nadic anhydride, hexahydro Selected from phthalic anhydride and mixed polybasic acid anhydrides.

C) Lubricating oil additive Optionally, the lubricating oil composition further comprises at least one lubricating oil additive or modifier (hereinafter “addition”) that can impart or improve any desired properties of the lubricating oil composition. May be included). Any lubricating oil additive known to those skilled in the art can be used in the lubricating oil compositions disclosed herein. Suitable additives are Mortier, et al., “Chemistry and Technology of Lubricants”, 2nd edition, London, Springer, (1996), and Leslie R. . As described by Leslie R. Rudnick, "Lubricant Additives: Chemistry and Applications", New York, Marcel Dekker, (2003), both Both are described in this specification as reference contents. In some embodiments, the lubricating oil additive may be an antioxidant, antiwear additive, detergent, rust inhibitor, demulsifier, friction modifier, multifunctional additive, pour point depressant, antifoam, metal It can be selected from the group consisting of deactivators, dispersants, corrosion inhibitors, thermal stability improvers, dyes, markers and combinations thereof.

  Generally, when using additives, each concentration in the lubricating oil composition is about 0.001% to about 10%, about 0.01% to about 0.01% by weight based on the total weight of the lubricating oil composition. It may be in the range of 5% by weight, or about 0.1% to about 2.5% by weight. Further, the total amount of additives in the lubricating oil composition may be about 0.001% to about 20%, about 0.01% to about 10%, or about 0, based on the total weight of the lubricating oil composition. It may be in the range of 1% to about 5% by weight.

1) Metallic detergents In some embodiments, the lubricating oil composition provided in the present invention contains at least one neutral or overbased metal detergent as an additive or additive component. In some embodiments, the metallic detergent of the lubricating oil composition acts as an acid product neutralizer in the oil. In some embodiments, the metallic detergent prevents the formation of engine surface deposits. Depending on the nature of the acid used, the detergent may have additional functions, such as antioxidant properties. In some embodiments, the lubricating oil composition contains a metallic detergent consisting of an overbased detergent or a mixture of neutral and overbased detergents. “Overbased” is intended to define an additive that contains an amount of metal in excess of that required by the stoichiometry of the particular metal and the particular organic acid used. Excess metal is present in the form of inorganic base particles surrounded by a metal salt covering, such as a hydroxide or carbonate. The wrap serves to maintain the particles in a dispersed state in the liquid oil vehicle. The amount of excess metal is usually expressed as the ratio of the total equivalents of excess metal to the equivalents of organic acid, generally 0.1 to 30.

  Non-limiting examples of suitable metallic detergents include sulfurized or unsulfurized alkyl or alkenyl phenates, alkyl or alkenyl aromatic sulfonates, borated sulfonates, sulfurized or polyhydroxyalkyl or alkenyl aromatic compounds or Unsulfurized metal salts, alkyl or alkenyl hydroxy aromatic sulfonates, sulfurized or unsulfurized alkyl or alkenyl naphthenates, metal salts of alkanolic acid, metal salts of alkyl or alkenyl polyacids, and chemical and physical mixtures thereof Can be mentioned. Other non-limiting examples of suitable metal detergents include metal sulfonates, phenates, salicylates, phosphonates, thiophosphonates, and combinations thereof. The metal may be any metal suitable for making sulfonate, phenate, salicylate or phosphonate detergents. Non-limiting examples of suitable metals include alkali metals, alkali metals and transition metals. In some embodiments, the metal is Ca, Mg, Ba, K, Na, Li, or the like. Typical metallic detergents that can be used in the lubricating oil composition include overbased calcium phenate.

  In general, the amount of metal detergent additive may be less than 10,000 ppm, less than 1000 ppm, less than 100 ppm, or less than 10 ppm based on the total weight of the lubricating oil composition. In some embodiments, the amount of metallic detergent is about 0.001% to about 5%, about 0.05% to about 3%, or about 0.1%, based on the total weight of the lubricating oil composition. % By mass to about 1% by mass. Suitable detergents are described in Mortia, et al., “Lubricant Chemistry and Technology,” Second Edition, London, Springer, Chapter 3, p. 75-85 (1996), and Leslie R. Ludnick, “Lubricant Additives: Chemistry and Applications”, New York, Marcel Decker, Chapter 4, p. 113-136 (2003), both of which are incorporated herein by reference.

2) Abrasion Resistance and / or Extreme Pressure Agent The lubricating oil composition of the present invention can optionally contain an abrasion resistance or extreme pressure agent. Wear occurs in all devices where moving parts are in contact. That is, usually three conditions cause wear in the engine: (1) surface-to-surface contact, (2) surface-to-foreign matter contact, and (3) erosion by corrosive substances. Wear resulting from surface-to-surface contact is friction or adhesive wear, wear resulting from contact with a foreign object is abrasive wear, and wear resulting from contact with corrosive substances is corrosive wear. Fatigue wear is an additional type of wear that is common in devices that are not only in surface contact but also are subject to repeated stress over time. Abrasive wear can be prevented by installing an effective filtration mechanism to remove harmful debris. Corrosive wear can be treated by using additives that neutralize reactive species that can attack the metal surface. In order to suppress adhesive wear, it is necessary to use an additive called antiwear and extreme pressure (EP) agent.

  At optimum speed and load conditions, the metal surface of the device will be effectively separated by the lubricating film. Increased load, decreased speed, or otherwise deviating from such optimum conditions will promote metal-to-metal contact. This contact generally causes a temperature increase in the contact area due to frictional heat, and then the temperature increase leads to a decrease in the viscosity of the lubricating oil and thus a decrease in its film-forming ability. In some embodiments, antiwear additives and EP agents provide protection by a similar mechanism. In some embodiments, the EP additive requires a higher activation temperature and load than the antiwear additive.

  Most antiwear and extreme pressure agents include sulfur, chlorine, phosphorus, boron, or combinations thereof. Examples of compounds that prevent adhesive wear include, for example, alkyl or aryl disulfides and polysulfides, dithiocarbamates, chlorinated hydrocarbons, and phosphorus compounds such as alkyl phosphites, phosphates, dithiophosphates And alkenylphosphonic acid esters.

  Typical anti-wear additives that can be included in the lubricating oil compositions of the present invention include zinc dithiophosphate, dithiophosphate metal (eg Pb, Sb and Mo) salts, dithiocarbamate metal (eg Zn , Pb, Sb and Mo etc.) salts, fatty acid metal (eg Zn, Pb and Sb etc.) salts, boron compounds, phosphate esters, phosphites, amine salts of phosphate or thiophosphate, di Mention may be made of the reaction products of cyclopentadiene and thiophosphoric acid, and combinations thereof. The amount of anti-wear additive is about 0.01% to about 5%, about 0.05% to about 3%, or about 0.1% to about 3%, based on the total weight of the lubricating oil composition. It can be varied by about 1% by weight. Suitable anti-wear additives are Leslie R. Ludnick, “Lubricant Additives: Chemistry and Applications”, New York, Marcel Decker, Chapter 8, p. 223-258 (2003), which is also incorporated herein by reference.

  In certain embodiments, the antiwear additive is or includes a dihydrocarbon dithiophosphate metal salt, such as a zinc dialkyldithiophosphate compound. The metal of the dihydrocarbon dithiophosphate metal salt may be an alkali or alkaline earth metal, or may be aluminum, lead, tin, molybdenum, manganese, nickel or copper. In some embodiments, the metal is zinc. In another embodiment, the alkyl group of the dihydrocarbon dithiophosphate metal salt has from about 3 to about 22 carbon atoms, from about 3 to about 18 carbon atoms, from about 3 to about 12 carbon atoms, or from about 3 to about 3 carbon atoms. About 8. In further embodiments, the alkyl group may be linear or branched.

  The amount of the dihydrocarbon dithiophosphate metal salt, including the dialkyldithiophosphate zinc salt, in the disclosed lubricating oil composition is measured by its phosphorus content. In some embodiments, the disclosed lubricating oil composition has a phosphorus content of from about 0.01% to about 0.12%, from about 0.1% to about 0.10% by weight based on the total weight of the lubricating oil composition. Or about 0.2% to about 0.8% by weight.

A dihydrocarbon dithiophosphoric acid metal salt is first produced according to a known technique, usually by reacting one or more of alcohol and phenolic compounds with P ₂ S ₅ to produce dihydrocarbon dithiophosphoric acid (DDPA), Can be prepared by neutralizing the DDPA with a metal compound, such as a metal oxide, hydroxide or carbonate. In one embodiment, DDPA can be produced by reacting a mixture of primary and secondary alcohols with P ₂ S ₅ . In another embodiment, two or more dihydrocarbon dithiophosphoric acids can be produced, where one type of dithiophosphoric acid hydrocarbon group is entirely secondary in nature, but the remaining dithiophosphoric acid hydrocarbon groups. Is a first class property. A zinc salt can be produced by reacting a dihydrocarbon dithiophosphoric acid with a zinc compound. In some embodiments, basic or neutral zinc compounds are used. In another embodiment, zinc oxide, hydroxide or carbonate is used.

  In one embodiment, oil-soluble zinc dialkyldithiophosphate can be produced from the dialkyldithiophosphoric acid represented by the formula (II).

Wherein each of R ³ and R ⁴ is independently linear or branched alkyl, or linear or branched substituted alkyl. In some embodiments, the alkyl group has from about 3 to about 30 carbon atoms, or from about 3 to about 8 carbon atoms.

The dialkyldithiophosphoric acid of formula (II) can be prepared by reacting alcohols R ³ OH and R ⁴ OH (where R ³ and R ⁴ are as defined above) with P ₂ S _5. it can. In some embodiments, R ³ and R ⁴ are the same. In another embodiment, R ³ and R ⁴ are different. In a further embodiment, R ³ OH and R ⁴ OH are reacted with P ₂ S ₅ simultaneously. In a further embodiment, R ³ OH and R ⁴ OH are reacted sequentially with P ₂ S ₅ .

  Mixtures of hydroxyl alkyl compounds can also be used. These hydroxylalkyl compounds need not be monohydroxylalkyl compounds. In some embodiments, dialkyldithiophosphoric acids are prepared from mono, di, tri, tetra, and other polyhydroxyalkyl compounds or mixtures of two or more of the former. In another embodiment, the zinc dialkyldithiophosphate derived only from the primary alkyl alcohol is derived from a single primary alcohol. In a further embodiment, the single primary alcohol is 2-ethylhexanol. In some embodiments, the zinc dialkyldithiophosphate is derived only from secondary alkyl alcohols. In a further embodiment, the mixture of secondary alcohols is a mixture of 2-butanol and 4-methyl-2-pentanol.

The phosphorus pentasulfide reactant used in the dialkyldithiophosphoric acid production process may contain an amount of one or more of P ₂ S ₃ , P ₄ S ₃ , P ₄ S ₇ or P ₄ S ₉ . The composition itself may contain a small amount of free sulfur. In some embodiments, the phosphorus pentasulfide reactant is substantially free of any of P ₂ S ₃ , P ₄ S ₃ , P ₄ S ₇ and P ₄ S ₉ . In some embodiments, the phosphorus pentasulfide reactant is substantially free of free sulfur.

  In the present invention, the sulfated ash content of the total lubricating oil composition is less than 5% by weight, less than 4% by weight, less than 3% by weight, less than 2% by weight, or less than 1% by weight as measured by ASTM D874.

  In one aspect, the EP agent used in the lubricating oil composition of the present invention includes alkyl and aryl disulfides and polysulfides, dithiocarbamates, chlorinated hydrocarbons, dialkyl hydrogen phosphites, and alkyl phosphate salts. Can be mentioned. Methods for producing these EP agents are known in the art. For example, polysulfides are synthesized by reacting sulfur from an olefin with sulfur or a halogenated halogen, followed by dehydrohalogenation. Dialkyldithiocarbamate can be produced by neutralizing dithiocarbamic acid (which can be produced by reacting dialkylamine and carbon disulfide at low temperature) with a base such as zinc oxide or antimony oxide, or by activating alkyl acrylate or the like. Produced by adding dithiocarbamic acid to olefin.

  In some embodiments, the lubricating oil composition includes one or more EP agents. In one aspect, the use of more than one EP agent provides a synergistic effect. For example, a synergistic effect can be observed between a sulfur-containing EP agent and a chlorine-containing EP agent. A typical lubricating oil composition of the present invention comprises one or more EP agents selected from the following materials: zinc dialkyldithiophosphate (primary alkyl type and secondary alkyl type), sulfurized oil, diphenyl sulfide , Methyltrichlorostearate, chlorinated naphthalene, fluoroalkylpolysiloxane, and lead naphthenate.

3) Rust inhibitor (rust inhibitor)
Protection against rust is an important consideration when formulating lubricants. Without protection, rust ultimately causes metal loss, thereby reducing equipment integrity, resulting in engine performance degradation. Furthermore, corrosion exposes fresh metal that can wear rapidly, but will continue indefinitely due to metal ions that can be released into the liquid and act as pro-oxidants.

  The lubricating oil composition of the present invention can optionally contain a rust inhibitor that can prevent corrosion of metal surfaces. Any rust inhibitor known to those skilled in the art can be used in the lubricating oil composition. Although the rust inhibitor itself adheres to the metal surface to form a non-penetrable protective film, the protective film can be physically or chemically adsorbed on the metal surface. That is, film formation occurs when the inhibitor interacts with the metal surface at its polar end and associates with the lubricating oil at its non-polar end. Suitable rust inhibitors include, for example, various nonionic polyoxyethylene surfactants, specifically polyoxyethylene lauryl ether, polyoxyethylene higher alcohol ether, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl. Mention may be made of ethers, polyoxyethylene octyl stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitol monostearate, polyoxyethylene sorbitol monooleate, and polyethylene glycol monooleate. Suitable rust inhibitors also include other compounds such as monocarboxylic acids (eg 2-ethylhexanoic acid, lauric acid, myristic acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, behenic acid, and serotic acid. ), Oil-soluble polycarboxylic acids (for example, those produced from tall oil fatty acids, oleic acid, linoleic acid, etc.), alkenyl succinic acids in which the alkenyl group contains 10 or more carbon atoms (for example, tetrapropenyl succinic acid, tetra Decenyl succinic acid, and hexadecenyl succinic acid), long chain alphas having molecular weights in the range of 600 to 3000 daltons, omega-dicarboxylic acids, and combinations thereof. Further examples of rust inhibitors include metal soaps, fatty acid amine salts, metal salts of heavy sulfonic acids, partial carboxylic acid esters of polyhydric alcohols, and phosphate esters.

4) Demulsifier The lubricating oil composition of the present invention can optionally contain a demulsifier that can promote oil-water separation of the lubricating oil composition exposed to water or steam. Any demulsifier known to those skilled in the art can be used in the lubricating oil composition. Non-limiting examples of suitable demulsifiers include anionic surfactants (eg, alkylnaphthalene sulfonates and alkylbenzene sulfonates), nonionic alkoxylated alkylphenol resins, polymers of alkylene oxide (eg, poly Ethylene oxide, polypropylene oxide, and block copolymers of ethylene oxide and propylene oxide), esters of oil-soluble acids, polyoxyethylene sorbitan esters, and combinations thereof. In some embodiments, demulsifiers that can be used in the present invention include block copolymers of propylene oxide or ethylene oxide with initiators such as glycerol, phenol, formaldehyde resins, siloxanes, polyamines and polyols. In some embodiments, the polymer comprises about 20 to about 50% ethylene oxide. These materials concentrate at the water-oil interface to create a low viscosity zone, thereby promoting droplet aggregation and gravity push phase separation. Low molecular weight materials such as alkali metal or alkaline earth metal salts of dialkylnaphthalene sulfonic acids are also useful in certain applications. The amount of demulsifier is from about 0.01% to about 10%, from about 0.05% to about 5%, or from about 0.1% to about 3% by weight based on the total weight of the lubricating oil composition. % Can be changed. Suitable demulsifiers are described in Mortia, et al., “Lubricant Chemistry and Technology”, Second Edition, London, Springer, Chapter 6, p. 190-193 (1996), which is also incorporated herein by reference.

5) Friction modifier The lubricating oil composition of the present invention can optionally contain a friction modifier that can reduce the friction between moving parts. Any friction modifier known to those skilled in the art can be used in the lubricating oil composition. Friction modifiers are generally long-chain molecules with polar end groups and nonpolar linear hydrocarbon chains. The polar end groups physically adsorb to the metal surface or chemically react with the metal surface, while the hydrocarbon chains extend into the lubricating oil. The chains associate with each other and with the lubricating oil to form a strong lubricating film.

  Non-limiting examples of suitable friction modifiers include fatty carboxylic acids, derivatives of fatty carboxylic acids (eg, alcohols, esters, borated esters, amides and metal salts, etc.), mono, di or trialkyl substituted phosphoric acids. Or derivatives of phosphonic acids, mono-, di- or trialkyl-substituted phosphoric acids or phosphonic acids (eg esters, amides and metal salts), mono-, di- or trialkyl-substituted amines, mono- or dialkyl-substituted amides, and their Combinations can be mentioned.

  In one aspect, the friction modifier is a saturated fatty acid containing a chain of 13-18 carbon atoms. The amount of friction modifier is about 0.01% to about 10%, about 0.05% to about 5%, or about 0.1% to about 3%, based on the total weight of the lubricating oil composition. It can be changed by mass%. Suitable friction modifiers are described by Mortia, et al., “Lubricant Chemistry and Technology,” Second Edition, London, Springer, Chapter 6, p. 183-187 (1996), and Leslie R. Ludnick, “Lubricant Additives: Chemistry and Applications”, New York, Mercer Decker, Chapters 6 and 7, p. 171-222 (2003), both of which are incorporated herein by reference.

6) Pour Point Depressant The lubricating oil composition of the present invention can optionally contain a pour point depressant that can lower the pour point of the lubricating oil composition. Any pour point depressant known to those skilled in the art can be used in the lubricating oil composition. In some embodiments, the pour point depressant has one or more structural characteristics selected from the following: (1) polymer structure, (2) waxy and non-waxing components, (3) long side groups. Comb structure consisting of a short main chain with (4) wide molecular weight distribution. Non-limiting examples of suitable pour point depressants include polymethacrylates, alkyl acrylate polymers, alkyl methacrylate polymers, alkyl fumarate polymers, di (tetra-paraffin phenol) phthalate, tetra-paraffin phenol condensation. Products, condensates of chlorinated paraffin and naphthalene, alkylated naphthalenes, styrene esters, oligomerized alkylphenols, phthalates, ethylene / vinyl acetate copolymers, and combinations thereof. In one embodiment, the pour point depressant is selected from tetra (long chain) alkyl silicates, phenyl tristearyloxysilane, and pentaerythritol tetrastearate. In one embodiment, the pour point depressant includes an ethylene / vinyl acetate copolymer, a condensate of chlorinated paraffin and phenol, polyalkylstyrene, or the like. The amount of pour point depressant is from about 0.01% to about 10%, from about 0.05% to about 5%, or from about 0.1% to about 5%, based on the total weight of the lubricating oil composition. It can be changed at 3% by mass. Suitable pour point depressants are described by Mortia, ibid, "Lubricant Chemistry and Technology", 2nd Edition, London, Springer, Chapter 6, p. 187-189 (1996), and Leslie R. Ludnick, “Lubricant Additives: Chemistry and Applications”, New York, Marcel Decker, Chapter 11, p. 329-354 (2003), both of which are incorporated herein by reference.

7) Antifoaming agent The lubricating oil composition of the present invention can optionally contain an antifoaming agent or an antifoaming agent capable of breaking oil bubbles. Any antifoam or defoamer known to those skilled in the art can be used in the lubricating oil composition. Non-limiting examples of suitable antifoaming agents include silicone oils or polydimethylsiloxanes, fluorosilicones, alkoxylated fatty acids, polyethers (eg, polyethylene glycols), branched polyvinyl ethers, alkyl acrylates Mention may be made of polymers, alkyl methacrylate polymers, polyalkoxyamines, and combinations thereof. In some embodiments, the antifoaming agent comprises glycerol monostearate, polyglycol palmitate, trialkyl monothiophosphate, ester of sulfonated ricinoleic acid, benzoylacetone, methyl salicylate, glycerol monooleate, or glycerol dioleate. Including. The amount of antifoaming agent is about 0.01% to about 5%, about 0.05% to about 3%, or about 0.1% to about 1%, based on the total weight of the lubricating oil composition. It can be changed by mass%. Suitable antifoaming agents are described in Mortia, et al., “Lubricant Chemistry and Technology,” Second Edition, London, Springer, Chapter 6, p. 190-193 (1996), which is also incorporated herein by reference.

8) Metal deactivator In one embodiment, the lubricating oil composition of the present invention contains at least one metal deactivator. Non-limiting examples of suitable metal deactivators can include disalicylidene propylene diamine, triazole derivatives, thiadiazole derivatives, and mercaptobenzimidazoles.

9) Dispersant The lubricating oil composition of the present invention can optionally contain a dispersant that can prevent sludge, varnish and other deposits by suspending the particles in a colloidal state. In some embodiments, the dispersant performs these functions by one or more means selected from: (1) solubilizing polar foreign matter in the micelles, (2) aggregation of the particles and oil. To stabilize the colloidal dispersion in order to prevent separation from it, (3) even if such a product is produced, it is suspended in a bulk lubricating oil, (4) the soot is modified and aggregated And minimizing oil thickening, and (5) reducing the surface / interfacial energy of undesirable materials to reduce their tendency to adhere to the surface. Undesirable substances are generally the result of oxidative degradation of the lubricating oil, the reaction of chemically reactive species such as carboxylic acids with engine metal surfaces, or the decomposition of thermally unstable lubricating oil additives such as extreme pressure agents. As a result.

  In some embodiments, the dispersant molecule includes three distinct structural features: (1) a hydrocarbon group, (2) a polar group, and (3) a linking group or bond. In some embodiments, the hydrocarbon group is polymeric in nature and has a molecular weight of about 2000 Daltons or more, in one embodiment about 3000 Daltons or more, in another embodiment about 5000 Daltons or more, and in another embodiment about 8000 Daltons or more. . A variety of olefins such as polyisobutylene, polypropylene, polyalphaolefins and mixtures thereof can be used to produce suitable polymeric dispersants. In some embodiments, the polymeric dispersant is a polyisobutylene derived dispersant. Generally, the number average molecular weight of the polyisobutylene of these dispersants ranges from about 500 to about 3000 daltons, or in some embodiments from about 800 to about 2000 daltons, or in further embodiments from about 1000 to about 2000 daltons. In some embodiments, the polar group of the dispersant is derived from nitrogen or oxygen. Nitrogen-based dispersants are generally derived from amines. Amines from which nitrogenous dispersants are derived are often polyalkylene polyamines such as diethylenetriamine and triethylenetetraamine. Amine derived dispersants are also referred to as nitrogen or amine dispersants, while those derived from alcohols are also referred to as oxygen or ester dispersants. Oxygen-based dispersants are generally neutral, while amine-based dispersants are generally basic.

  Non-limiting examples of suitable dispersants include alkenyl succinimides, alkenyl succinimides modified with other organic compounds, alkenyl succinimides modified by post-treatment with ethylene carbonate or boric acid, succinic acid. Acid amides, succinic acid esters, succinic acid ester-amides, pentaerythritols, phenate-salicylates and their post-processed analogs, alkali metals or mixed alkali metals, alkaline earth metal borates, hydration There may be mentioned alkali metal borate dispersions, alkaline earth metal borate dispersions, polyamide ashless dispersants, benzylamines, Mannich type dispersants, phosphorus-containing dispersants, and combinations thereof. The amount of dispersant is from about 0.01% to about 10%, from about 0.05% to about 7%, or from about 0.1% to about 4% by weight based on the total weight of the lubricating oil composition. % Can be changed. Suitable dispersants are described in Mortia, et al., “Lubricant Chemistry and Technology,” Second Edition, London, Springer, Chapter 3, p. 86-90 (1996), and Leslie R. Ludnick, “Lubricant Additives: Chemistry and Applications”, New York, Marcel Decker, Chapter 5, p. 137-170 (2003), both of which are incorporated herein by reference.

10) Antioxidants Optionally, the lubricating oil compositions of the present invention can further contain additional antioxidants that can reduce or prevent oxidation of the base oil. Any antioxidant known to those skilled in the art can be used in the lubricating oil composition. Examples of antioxidants that can be used in the present invention include, but are not limited to, phenolic (phenolic) antioxidants such as 4,4′-methylene-bis (2,6-di-tert). -Butylphenol), 4,4'-bis (2,6-di-tert-butylphenol), 4,4'-bis (2-methyl-6-tert-butylphenol), 2,2'-methylene-bis (4 -Methyl-6-tert-butylphenol), 4,4'-butylidene-bis (3-methyl-6-tert-butylphenol), 4,4'-isopropylidene-bis (2,6-di-tert-butylphenol) 2,2′-methylene-bis (4-methyl-6-nonylphenol), 2,2′-isobutylidene-bis (4,6-dimethylphenol), 2,2 ′, 5-methylene Bis (4-methyl-6-cyclohexylphenol), 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,4-dimethyl-6 tert-butylphenol, 2,6-di-tert-1-dimethylamino-p-cresol, 2,6-di-tert-4- (N, N′-dimethylaminomethylphenol), 4,4′-thiobis ( 2-methyl-6-tert-butylphenol), 2,2′-thiobis (4-methyl-6-tert-butylphenol), bis (3-methyl-4-hydroxy-5-tert-10-butylbenzyl) -sulfide And bis (3,5-di-tert-butyl-4-hydroxybenzyl). Diphenylamine type antioxidants include, but are not limited to, alkylated diphenylamine, phenyl-alpha-naphthylamine, and alkylated alpha-naphthylamine, sulfur-based antioxidants (eg, dilauryl-3,3′- Thiodipropionate and sulfurized phenol-based antioxidants), phosphorus-based antioxidants (for example, phosphites), zinc dithiophosphate, oil-soluble copper compounds, and combinations thereof. Other types of antioxidants include metal dithiocarbamates (eg, zinc dithiocarbamate), and 15-methylenebis (dibutyldithiocarbamate). The amount of antioxidant is about 0.01% to about 10%, about 0.05% to about 5%, or about 0.1% to about 3%, based on the total weight of the lubricating oil composition. It can be changed by mass%. Suitable antioxidants are Leslie R.A. Ludnick, "Lubricant Additives: Chemistry and Applications", New York, Marcel Decker, Chapter 1, p. 1-28 (2003), which is also incorporated herein by reference.

11) Multifunctional Additives Various additives described or not described herein can have multiple effects on the lubricating oil composition of the present invention. Thus, for example, a single additive can act both as a dispersant and as an antioxidant. Multifunctional additives are well known in the art. Other suitable multifunctional additives include, for example, sulfurized oxymolybdenum dithiocarbamate, sulfurized oxymolybdenum organophosphorodithioate, oxymolybdenum monoglyceride, amine-molybdenum complex, and sulfur-containing molybdenum complex.

12) Viscosity index improver In one embodiment, the lubricating oil composition of the present invention contains at least one viscosity index improver. Non-limiting examples of suitable viscosity index improvers include polymethacrylate type polymers, ethylene / propylene copolymers, styrene / isoprene copolymers, hydrated styrene / isoprene copolymers, polyisobutylene, and dispersed types. Mention may be made of viscosity index improvers.

D) Manufacturing Method of Lubricating Oil Composition The lubricating oil composition of the present invention can be manufactured by any lubricating oil manufacturing method known to those skilled in the art. In some embodiments, the base oil is blended or mixed with the ester base stock and optionally additives. In some embodiments, the base oil is added after premixing the ester base stock. The ester base stock combination and optional additives may be added separately or simultaneously to the base oil. In some embodiments, the ester base stock combination and optional additives are added separately to the base oil in one or more additions, but the additions may be in any order. In another embodiment, the ester base stock and additive are added simultaneously to the base oil. In one aspect, the ester base stock having a kinematic viscosity of 2-10 cSt and / or an ester base stock having a kinematic viscosity of greater than 10 and up to 50 cSt prior to the addition of the ester base stock having a kinematic viscosity greater than 100 cSt Add to base oil.

  Any mixing or dispersing device known to those skilled in the art can be used to blend, mix or solubilize the components.

E) Use of Lubricating Oil Composition In one aspect, the lubricating oil composition provided by the present invention is suitable for high power engines such as those found in racing cars and sports cars. In one aspect, the lubricating oil composition of the present invention achieves higher wear protection and less energy loss, even under extremely severe operating conditions due to high power engines. In one aspect, the extreme pressure performance of such engines has been demonstrated by improvements in the Falex test (ASTM D3233 method B). In one aspect, the lubricating oil composition minimizes or eliminates the corrosive effects of such extreme pressure agents with the lubricating oil composition by minimizing or eliminating the use of other extreme pressure agents. In some embodiments, the lubricating oil formulations of the present invention improve the shear stability of the oil. In one aspect, the lubricating oil composition of the present invention improves hydraulic stability.

  The following examples are presented to illustrate aspects of the lubricating oil composition of the present invention and are not intended to be limited to the specific aspects presenting the content of the invention. Unless otherwise indicated, all parts and percentages are by weight. All numbers are approximate. Where numerical ranges are given, aspects outside the stated ranges should still be construed as being included within the scope of the claimed invention. Specific details described in each example should not be construed as necessary features of the claimed subject matter.

  In the examples, the base oils described below are used in the lubricating oil composition.

Table 1 ────────────────────────────────────
Base oil Kinematic viscosity at 40 ° C Kinematic viscosity at 100 ° C Viscosity index
(CSt) (cSt)
────────────────────────────────────
Chevron UCBO4R 19 4.1 127
Chevron UCBO7R 39 7.0 135
Priore 3960 19.0 4.5 163
Ketogen Roube 135 344.2 34.2 142
Priore 3986 47000 2000 278
────────────────────────────────────

  Chevron UCBO4R and UCBO7R are commercially available Group III base oils. Priolube 3960 is a diester based on saturated short chain fatty acids, but is a low viscosity synthetic ester base stock commercially available from Croda. Ketjenlube 135 is a butanol ester of an α-olefin / maleic acid copolymer having a molecular weight of about 1800, but is a medium viscosity synthetic ester base stock commercially available from Akzo Nobel. is there. Priore 3986 is a complex ester, but is a high viscosity synthetic ester base stock commercially available from Kuroda.

[Comparative Example 1-3]
The lubricating oil composition of Comparative Example 1-3 was produced according to the formulation presented in Table 1. The composition of Comparative Example 1-3 has three different SAEs by adding varying amounts of non-dispersed viscosity index improvers and / or by changing the ratio of the two Type III base stocks. (American Automotive Engineers Association) Adjusted to a viscosity grade. These lubricating oil compositions contain one or more Type III base stocks in major amounts, but do not contain synthetic ester base stocks.

[Embodiment 4-6 of the present invention]
Three different viscosity grades were prepared by preparing the lubricating oil compositions of Examples 4-6 according to the formulations presented in Table 1 and adding high viscosity synthetic ester base stock (priorube 3986) in varying amounts. Adjusted. These lubricating oil compositions contain a major amount of one or more Group III base stocks and also include a combination of low, medium and high viscosity synthetic ester base stocks.

(Extreme pressure test performance)
The Falex test (ASTM D3233 method B) is a bench test that measures the extreme pressure characteristics of a liquid lubricant. This method involves rotating a rotating steel journal at 290 ± 10 rpm against two stationary V-blocks immersed in a lubricant sample. A load is applied to the V block by the ratchet mechanism. In Test Method B, the load was applied in increments of 250-lbf (1112-N) and maintained for 1 minute without changing the load for each increment of load. The obtained unacceptable load value is a criterion for determining the load bearing characteristic level.

  Table 2 gives an overview of the viscosity characteristics and extreme pressure wear protection performance of Comparative Examples 1-3 and Examples 4-6.

Table 2 ──────────────────────────────────────
Comparative Example / Example 1 2 3 4 5 6
─────────────────────────────────────
SAE oil viscosity 5W30 0W20 10W40 0W20 5W20 5W30
Additive package 1 ¹ (wt%) 9.1 9.1 9.1---
Additive Package 2 ² (wt%)---8.25 8.25 8.25
Abrasion resistance additive (wt%) 0.80 0.22 0.80---
Friction modifier (wt%) 0.30 0.70 0.30---
Defoamer (wt%) 0.02 0.02 0.02---
Non-dispersed olefin 8.69 5.35 8.00---
Copolymer VII ³ (wt%)
Priore 3960 (wt%)---18.00 18.00 18.00
Ketogen Roube 135 (wt%)---14.00 14.00 14.00
Priore 3986 (wt%)---2.00 4.00 6.00
Chevron UCBO4R (wt%) 51.49 74.59-57.75 55.75 53.75
Chevron UCBO7R (wt%) 29.59 10.02 81.77---
Kinematic viscosity (100 ° C) (cSt) 10.49 7.59 13.47 7.06 8.26 9.55
Kinematic viscosity (40 ° C) (cSt) 58.51 39.2 86.19 36.52 43.89 51.66
Viscosity index 171 165 159 159 166 172
─────────────────────────────────────

Table 2 (continued)
─────────────────────────────────────
Comparative Example / Example 1 2 3 4 5 6
─────────────────────────────────────
HTHS (150 ° C) (cP) 3.05 2.57 3.70 2.79 3.10 3.58
HTHS (100 ° C) (cP) 6.90 5.34 8.68 5.79 6.10 7.44
HTHS (50 ° C) (cP) 23.91 17.93 31.84 19.55 22.61 26.51
CCS (-35 ° C) (cP)-4585-5650--
CCS (-30 ° C) (cP) 3405---4190 5518
CCS (−25 ° C) (cP)--4223---
Falex test ⁴
(ASTM D3233 B)
First failure load (lb) 1250 1250-2000 2250 3250
Second fail load (lb) 1250 1250-2000 4500 1750
Third failure load (lb)----3500 3750
─────────────────────────────────────
¹ : Additive package includes borated dispersant, ethylene carbonate post-treatment dispersant, overbased detergent, zinc-containing antiwear additive, molybdenum-containing friction modifier, ashless friction modifier, antioxidant, anti-oxidant Contains foam and diluent oil.
² : Additive package is borated dispersant, ethylene carbonate aftertreatment dispersant, overbased detergent, mixture of two kinds of zinc-containing antiwear additives, two kinds of molybdenum-containing friction modifiers, antifoaming agents And contains diluent oil.
³ : Ethylene / propylene copolymer viscosity index improver manufactured by Chevron Oronite Company LLC.
⁴ : The third test was performed only when the first and second results were different.

  As the data demonstrate, the lubricating oil compositions of Examples 4-6 exhibit high HTHS at 150 ° C. and are useful for wear protection in extreme conditions. Examples 4-6 also show excellent load bearing characteristics as evidenced by improvements in the Falex extreme pressure wear test.

(Friction test performance)
For the lubricating oil compositions of Comparative Examples 1, 2, and 3 and the lubricating oil compositions of Examples 4, 5, and 6, the traction coefficient was measured using a small friction machine (MTM) test apparatus. The test is defined as the slip ratio (the difference between the sliding speed between the sphere and the disk divided by the average speed of the sphere and the disk. SRR = (speed 1−speed 2) / ((speed 1 + speed 2) / 2)) Performed at 25%, 50%, 75% and 100%. Data for each oil traction coefficient was plotted against disk speed. A plot is presented in FIGS. 1-4.

  As demonstrated in FIGS. 1-4, the composition of Example 4-6 exhibits a lower traction coefficient at any disk speed than the lubricating oil composition of Comparative Example 1-3.

  Although the lubricating oil composition provided by the present invention has been described with a limited number of embodiments, the particular features of one embodiment should not be considered to be in other embodiments of the claimed subject matter. No single embodiment is representative of all aspects of the claimed subject matter. In certain embodiments, the method may include a number of steps not described herein. In another embodiment, steps not listed herein are not included or substantially not included in the method. There are variations and modifications from the described embodiments. It should be noted that the process for producing the composition of the present invention is described using a number of steps. These steps can be performed in any order. One or more steps may be omitted or combined, but still substantially the same result can be achieved. The appended claims are intended to cover all such modifications and changes as fall within the scope of the claims.

  All publications and patent application specifications mentioned in this specification are hereby incorporated by reference to the same extent as if each individual publication or patent application specification was clearly and individually suggested as a reference. It is said that. Although the above content has been described in some detail by way of explanation and examples for the sake of clarity of understanding, certain changes and modifications may be made to the above content without departing from the spirit or scope of the appended claims. Those skilled in the art will readily appreciate the teachings of the present invention.

Claims (28)

A lubricating oil composition comprising a combination of a Group III base oil and an ester base stock comprising the following ingredients:
(A) an ester base oil having a kinematic viscosity of 100 ° C and 2-10 cSt,
(B) an ester base stock having a kinematic viscosity higher than 10 at 100 ° C. up to 50 cSt, and (c) an ester base stock having a kinematic viscosity higher than 100 cSt at 100 ° C.   The lubricating oil composition of claim 1, wherein the Group III base oil is greater than about 50% by total weight of the lubricating oil composition.   The lubricating oil composition of claim 1, wherein the Group III base oil is about 58% by total weight of the lubricating oil composition.   The lubricating oil composition of claim 1, wherein the Group III base oil is about 54% by total weight of the lubricating oil composition.   The lubricating oil composition according to claim 1, wherein the kinematic viscosity of the Group III base oil is 4.1 cSt or 7 cSt at 100 ° C.   The lubricating oil composition of claim 1, wherein the ester base stock combination is less than about 50% by weight of the total weight of the lubricating oil composition.   The lubricating oil composition of claim 1, wherein the ester base stock combination is about 38% by weight of the total weight of the lubricating oil composition.   The lubricating oil composition of claim 1, wherein the ester base stock combination is about 36% by weight of the total weight of the lubricating oil composition.   The lubricating oil composition of claim 1, wherein the ester base stock combination is about 34% by weight of the total weight of the lubricating oil composition.   The lubricating oil composition according to claim 1, wherein the ester base oil (a) comprises a diester based on short chain fatty acids.   The lubricating oil composition according to claim 1, wherein the ester base stock (a) comprises a diester based on a short-chain fatty acid having a kinematic viscosity at 100 ° C of 4.5 cSt.   The lubricating oil composition according to claim 1, wherein the ester base oil (b) comprises a polymer ester.   The lubricating oil composition according to claim 1, wherein the ester base stock (b) comprises a butanol ester of an α-olefin / maleic acid copolymer.   The lubricating oil composition according to claim 1, wherein the ester base oil (b) comprises a polymer ester having a kinematic viscosity at 100 ° C. of 34 cSt.   The lubricating oil composition according to claim 1, wherein the ester base oil (c) contains a complex ester having a kinematic viscosity at 100 ° C. of 2000 cSt.   The lubricating oil composition of claim 1, wherein the amount of ester base stock (a) is between about 10% and about 25% by weight of the total weight of the composition.   The lubricating oil composition of claim 1, wherein the amount of ester base stock (a) is about 18% by weight of the total weight of the composition.   The lubricating oil composition of claim 1, wherein the amount of ester base stock (b) is between about 10% and about 20% by weight of the total weight of the composition.   The lubricating oil composition of claim 1, wherein the amount of ester base stock (b) is about 14% by weight of the total weight of the composition.   The lubricating oil composition of claim 1, wherein the amount of ester base stock (c) is between about 1% and about 10% by weight of the total weight of the composition.   The lubricating oil composition of claim 1, wherein the amount of ester base stock (c) is about 2% by weight of the total weight of the composition.   The lubricating oil composition of claim 1, wherein the amount of ester base stock (c) is about 4% by weight of the total weight of the composition.   The lubricating oil composition of claim 1, wherein the amount of ester base stock (c) is about 6% by weight of the total weight of the composition.   In addition, antioxidants, anti-wear additives, detergents, rust inhibitors, anti-emulsifiers, friction modifiers, multifunctional additives, viscosity index improvers, pour point depressants, antifoaming agents, metal deactivation The lubricating oil composition according to claim 1, comprising at least one additive selected from the group consisting of an agent, a dispersant, a corrosion inhibitor, a lubricity improver, and combinations thereof. A method for producing a lubricating oil composition comprising the step of mixing the following substances:
(I) Type III base oil, and (ii) A combination of ester base stocks comprising the following components:
(A) an ester base oil having a kinematic viscosity of 100 ° C and 2-10 cSt,
(B) an ester base stock having a kinematic viscosity higher than 10 at 100 ° C. up to 50 cSt, and (c) an ester base stock having a kinematic viscosity higher than 100 cSt at 100 ° C.   A method of lubricating a high power engine comprising the step of operating the engine with the lubricating oil composition of claim 1.   27. The method of claim 26, wherein the high power engine is a race car engine or a sports car engine.   27. The method of claim 26, wherein the high power engine is a racing motorcycle engine or a sports motorcycle engine.

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